JP5791272B2 - Flange back mechanism - Google Patents

Description

  The present invention relates to a flange back mechanism that determines a distance from a lens mount of a camera to an image sensor (hereinafter referred to as a flange back distance), for example.

In the flange back mechanism of the camera, the holder for holding the lens and the holder for holding the image sensor (CCD) expand and contract as the temperature changes to a high temperature, and the flange back distance varies. When the flange back distance fluctuates, as shown in FIG. 7, a deviation occurs between the imaging plane of the lens and the imaging element surface. When the deviation exceeds the depth of focus, the focus is shifted and the blur is recognized in the image.
For example, according to Patent Document 1, a conventional flange back mechanism linearly expands into a first holder for fixing a lens and a second holder for fixing an image pickup device in order to reduce fluctuations in the flange back distance due to temperature changes. Another material with a different coefficient is used, and the end of the second holder is attached to the end of the first holder. Due to temperature changes, the first holder and the second holder are in opposite directions along the optical axis. The linear expansion is performed.

Japanese Patent Laid-Open No. 04-104211

  However, since the flange back mechanism of Patent Document 1 reduces the amount of variation in the flange back distance due to the difference in the linear expansion amount between the first holder and the second holder in the optical axis direction, the dimension in the optical axis direction is small. There was a problem that the camera lengthened and led to an increase in the size of the camera.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a flange back mechanism that can reduce the size of the camera and reduce the variation amount of the flange back distance.

A flange back mechanism according to the present invention includes a holder that holds a lens that forms an image through light from the outside, a plate that is fitted to the holder and that holds the image sensor on a surface facing the lens, and has a larger linear expansion coefficient than the holder. The cross section of the movable holder or the fitting of the holder to at least one fitting surface of the movable holder, the side surface of the movable holder that fits the holder and the side surface of the fitting hole formed in the holder that fits the movable holder An inclined part formed so that the cross section of the hole narrows along the optical axis direction from the lens toward the image sensor, and the side surface of the movable holder on the side surface of the fitting hole of the holder. The movable holder moves along the inclined portion so as to reduce the amount of fluctuation in the optical axis direction of the holder holding the lens in accordance with a temperature change .

According to the flange back mechanism according to the present invention, the movable holder can be shifted in the direction of the optical axis in accordance with the temperature change without applying an extra force to the lens and the holder that holds the lens. For example, the image pickup element surface can be shifted in the lens direction by the movable holder protruding into the holder as the temperature rises . As a result, without adversely affecting the lens and the holder that holds the lens, the flange back mechanism can be thinned to reduce the size of the camera, and the variation amount of the flange back distance can be reduced.

It is a whole perspective view which notched a part of flange back mechanism concerning Embodiment 1 of this invention. It is sectional drawing of the flange back mechanism seen from the notch part of FIG. It is a figure which shows the state of a flange back mechanism when the temperature changes to high temperature in FIG. It is the whole perspective view which notched a part of flange back mechanism concerning Embodiment 2 of this invention. It is sectional drawing of the flange back mechanism seen from the notch part of FIG. It is a figure which shows the state of a flange back mechanism when the temperature changes to high temperature in FIG. It is a figure which shows a state when the temperature changes to high temperature in the conventional flange back mechanism.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a perspective view of the flange back mechanism according to Embodiment 1 with a part cut away.
The flange back mechanism 1 includes a holder 10 as a lens holder, a movable holder 14 as a sensor holder, a lens 110, an image sensor 120, a sensor substrate 130, a post 150, and a spring (elastic member) 160. When the movable holder 14 is combined, a hollow cylindrical shape is obtained.
The lens 110 is configured to transmit light from the outside in the direction of the optical axis A and form an image inside the holder 10.
The image sensor 120 is an electronic component that converts light from the lens 110 into an electrical signal, and is mounted on the sensor substrate 130.

The holder 10 includes a disk-shaped chassis 11 and a fixed holder portion 12 fixed to the chassis 11.
The chassis 11 has an attachment hole for attaching the lens 110 in the center of the disk shape, and holds the lens 110 on the outside side by the attachment hole.
A shaft-shaped post 150 is attached to the inner surface of the chassis 11, and a spring 160 is passed through each post 150.
One end of the post 150 is attached to the inner surface of the chassis 11, and the other end is provided through the movable holder 14. Here, three posts 150 are provided, and are arranged at equal intervals.
The spring 160 passed through the post 150 is disposed between the chassis 11 of the holder 10 and the movable holder 14 and is provided as an elastic member that presses the movable holder 14 in the optical axis direction of the lens 110.

  The fixed holder portion 12 has substantially the same diameter as the chassis 11 and is fixed to the chassis 11 by screwing to form a hollow portion of the holder 10. A hole for accommodating the movable holder 14 is formed in the fixed holder portion 12 so as to face the chassis 11, and the side surface of the movable holder 14 is used as a fitting surface for fitting the movable holder 14 to the edge of the hole. It has the inclination part 19 which inclines at the same angle as a part.

The movable holder 14 has a disk shape, and has an inclined portion 19 as a fitting surface with the fixed holder portion 12 on a side surface portion thereof.
The movable holder 14 is fitted to the fixed holder portion 12 of the holder 10 with the inclined portion 19 as a fitting surface, and is pressed and supported in the optical axis direction of the lens 110 by the elastic force of the spring 160.
A sensor substrate 130 on which the image sensor 120 is mounted is disposed on the movable holder 14 so as to face the lens 110, and the image sensor 120 is attached so as to be positioned on the optical axis A of the lens 110.
The movable holder 14 is made of a material having a larger linear expansion coefficient than that of the holder 10 that holds the lens 110, and is larger than the amount of expansion in the direction perpendicular to the optical axis of the holder 10 when the temperature changes to a high temperature. It is configured to linearly expand with an expansion amount.

  The inclination angle of the inclined portion 19 as a fitting surface between the holder 10 and the movable holder 14 is formed so that the diameter becomes narrower along the optical axis direction of the lens 110. By forming in this way, when the holder 10 and the movable holder 14 are linearly expanded due to a temperature change, the fitting surface of the holder 10 and the movable holder 14 is displaced, and the movable holder 14 is moved to the inside of the holder 10. Can do.

  Here, the flange back mechanism 1 is configured to be able to adjust the amount of movement of the variable holder 14 in accordance with the ratio between the diameter of the holder 10 and the movable holder 14 and the dimension of the holder 10 that holds the lens 110 in the optical axis direction. Yes. In FIG. 1, the diameters of the holder 10 and the movable holder 14 are formed larger than the dimension in the optical axis direction of the holder 10 that holds the lens 110, and the larger the diameter, the movement of the movable holder 14 in the flange back mechanism 1. The amount can be increased, and the imaging element surface on the sensor substrate 130 held by the movable holder 14 can follow the imaging surface of the lens 110.

FIG. 2 is a cross-sectional view of the flange back mechanism as viewed from the notched portion in FIG.
The lens mount 200 is a surface where the lens 110 is abutted against the chassis 11, and the focusing surface 210 of the lens 110 is in the same position as the imaging element surface 220 on the surface of the imaging element 120 in a focused state. The flange back distance a represents the distance from the lens mount 200 to the imaging element surface 220. Here, in general, the focus is adjusted before the temperature change (normal temperature), and the holder 10 and the movable holder 14 are fitted in the entire inclined portion 19 as shown in FIG.

Next, operation | movement of the flange back mechanism 1 of Embodiment 1 is demonstrated using FIG.
In the flange back mechanism 1, when the temperature changes to a high temperature, as shown in FIG. 3, the holder 10 linearly expands and extends in the direction c perpendicular to the optical axis, and the side surface portion 10a of the holder 10 linearly expands to the optical axis direction d. To grow.
On the other hand, the movable holder 14 also linearly expands and extends in the direction e perpendicular to the optical axis. Here, since the movable holder 14 uses a material having a larger linear expansion coefficient than the holder 10, the movable holder 14 extends more than the amount of linear expansion of the chassis 11 of the holder 10 in the direction perpendicular to the optical axis. The fitting between the holder 10 and the movable holder 14 is shifted at the inclined portion 19, and the movable holder 14 resists the elastic force of the spring 160, and protrudes inside the holder 10 along the inclined portion 19. The sensor substrate 130 and the image sensor 120 attached to the movable holder 14 are shifted in a direction approaching the lens mount 200 parallel to the optical axis.
As described above, the amount of shift of the side surface portion 10a of the holder 10 in the direction away from the lens mount 200 and the amount of shift of the movable holder 14 in the direction of approaching the lens mount 200 are reduced, thereby causing a change in temperature. The amount of fluctuation of the flange back distance a is reduced.

  As described above, the flange back mechanism 1 according to the first embodiment includes the holder 10 that holds the lens 110 that forms an image through light from the outside, the movable holder 14 that holds the image sensor 120, and the lens 110. An inclined portion 19 which is formed on a fitting surface for fitting the holder 10 and the movable holder 14 and is inclined along the optical axis A direction of the lens 110, and the holder 10 and the movable holder 14. Since the spring (elastic member) 160 disposed between them and pressing the movable holder 14 in the direction of the optical axis A is provided, the movable holder 14 linearly expands in the direction perpendicular to the optical axis due to a temperature change, and the inclined portion. The image sensor surface can be moved by shifting so as to protrude into the holder 10 along the line 19. As a result, it is possible to reduce the size of the camera and reduce the amount of variation in the flange back distance.

  Further, the flange back mechanism 1 of the first embodiment can support the movable holder 14 by pressing it in the optical axis direction of the lens 110 even with a spring 160 having a small elastic force by forming the diameter of the movable holder 14 small. it can.

Embodiment 2. FIG.
In the first embodiment, the configuration using the movable holder 14 has been described. In the second embodiment, a configuration using a movable holder having a larger diameter than that of the movable holder 14 of the first embodiment will be described.
FIG. 4 is a perspective view of the flange back mechanism according to Embodiment 2 with a part cut away. The flange back mechanism 2 includes a holder 20, a movable holder 24, a lens 110, a sensor substrate 130, an image sensor 120, a post 150, and a spring 160. When the holder 20 and the movable holder 24 are combined, a hollow cylindrical shape is formed. Here, since the configurations other than the sizes of the holder 20 and the movable holder 24 in FIG. 4 are the same as those in the first embodiment, the same reference numerals as those in FIG. Description other than that is omitted.

The fixed holder portion 22 of the holder 20 is formed so that the diameter of the hole for accommodating the movable holder 24 facing the chassis 21 is larger than that of the configuration of the first embodiment.
The diameter of the movable holder 24 is larger than the diameter of the movable holder 14 of the first embodiment, and is formed to have a diameter substantially the same as the diameter of the holder 20 that holds the lens 110, for example. The movable holder 24 is configured to have a large diameter so that when the temperature changes to a high temperature and linearly expands, the amount of expansion in the direction perpendicular to the optical axis of the lens 110 increases. Note that the movable holder 24 can be adjusted in advance in the direction perpendicular to the optical axis of the lens 110 by being formed with a diameter corresponding to the amount of temperature change in advance.

FIG. 5 is a cross-sectional view of the flange back mechanism as seen from the notched portion in FIG.
The lens mount 200 is a surface that abuts the lens 110 against the chassis 21, and the image forming surface 210 of the lens 110 is in the same position as the image sensor surface 220 on the surface of the image sensor 120 in a focused state. The flange back distance a represents the distance from the lens mount 200 to the imaging element surface 220. Here, in general, the focus is adjusted before the temperature change (normal temperature), and the holder 20 and the movable holder 24 are fitted in the entire inclined portion 29 as shown in FIG.

Next, operation | movement of the flange back mechanism 2 of Embodiment 2 is demonstrated using FIG.
When the temperature of the flange back mechanism 2 changes to a high temperature, as shown in FIG. 6, the chassis 21 of the holder 20 linearly expands and extends in the direction c ′ perpendicular to the optical axis, and the side surface portion 20a of the holder 20 linearly expands to generate light. It extends in the axial direction d ′.
On the other hand, the movable holder 24 also linearly expands and extends in the direction e ′ perpendicular to the optical axis. Here, since the movable holder 24 uses a material having a larger linear expansion coefficient than the holder 20, the movable holder 24 extends more than the amount of linear expansion of the chassis 21 of the holder 20 in the direction perpendicular to the optical axis. Moreover, since the movable holder 24 has a larger diameter than the movable holder 14 of the first embodiment, the amount of linear expansion is increased. The fitting between the holder 20 and the movable holder 24 is shifted at the inclined portion 29, and the movable holder 24 resists the elastic force of the spring 160 and protrudes inside the holder 20 along the inclined portion 29. The sensor substrate 130 and the image sensor 120 attached to the movable holder 24 shift in a direction parallel to the optical axis and approaching the lens mount 200.
As described above, when the temperature changes to a high temperature and the holder 20 expands and changes in the optical axis direction, the imaging element surface 220 is made to follow the imaging surface 210 of the lens 110, thereby causing a flange due to the temperature change. The amount of fluctuation of the back distance a is reduced.

  As described above, the flange back mechanism 2 according to the second embodiment is formed with a diameter corresponding to the amount of temperature change, and has a larger diameter (the lens 110 than the diameter of the movable holder 14 according to the first embodiment, for example. The movable holder 24 is configured so as to have the imaging element surface 220 follow the imaging surface 210 of the lens 110 even when the temperature changes greatly. Can be shifted.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  1, 2 Flange back mechanism, 10, 20 holder, 11, 21 chassis, 12, 22 fixed holder part, 14, 24 movable holder, 19, 29 inclined part, 110 lens, 120 image sensor, 130 sensor substrate, 150 post, 160 Spring, 200 Lens mount, 210 Imaging surface, 220 Image sensor surface.

Claims (3)

A holder for holding a lens that forms an image through light from the outside;
A plate-shaped movable holder that is fitted to the holder and holds the image sensor on the surface facing the lens, and has a larger linear expansion coefficient than the holder;
The cross section of the movable holder or the fitting of the holder to at least one fitting surface of the side surface of the movable holder fitted to the holder and the side surface of the fitting hole formed in the holder fitted to the movable holder An inclined portion formed so that the cross section of the hole becomes narrower along the optical axis direction from the lens toward the imaging element;
An elastic member that is disposed between the holder and the movable holder and presses the side surface of the movable holder so as to contact the side surface of the fitting hole of the holder ;
The flange-back mechanism , wherein the movable holder moves along the inclined portion so as to reduce a variation amount of the holder holding the lens in the optical axis direction in accordance with a temperature change .   2. The flange back mechanism according to claim 1, wherein a diameter of the holder and the movable holder is larger than a dimension of the holder for holding the lens in an optical axis direction.   The flange back mechanism according to claim 1, wherein the movable holder has substantially the same diameter as the holder that holds the lens.

Images